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CGILS Updated Results

Minghua Zhang (Stony Brook University)

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CGILS Updated Results

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  1. Minghua Zhang (Stony Brook University) Julio Bacmeister, Sandrine Bony, Chris Bretherton, FlorentBrient, Anning Cheng, Stephan de Roode,Tony Del Genio, Charmaine Franklin, Chris Golaz, Cecile Hanny, Francesco Isotta, In-Sik Kang, Hideaki Kawai, Martin Koehler, Suvarchal Kumar, Vince Larson, Adrian Lock, Ulrike Lohman, Marat Khairoutdinov, Andrea Molod, RoelNeggers, Sing-Bin Park, Ryan Senkbeil, Pier Siebesma, ColombeSiegenthaler-Le Drian, Bjorn Stevens, Max Suarez, Kuan-man Xu, Mark Webb, Audrey Wolfe, Ming Zhao, CGILS Updated Results GCSS-BLCWG Meeting, September 29-30, 2010 KNMI

  2. s12 S11 S6 GPCI

  3. Purpose: To understand the causes of cloud feedbacks, and thus climate sensitivities of climate models. Objectives: To understand the physical mechanisms of cloud feedbacks in SCMs To interpret GCM cloud feedbacks by using SCM results To Evaluate the SCM cloud feedbacks using LES simulations

  4. RH Fixed (moist adiabat) T(z) T(z) Warm Pool Cold Tongue CGILS (CFMIP-GCSS Intercomparison of Large-Eddy and Single-Column Models) Need to be relevant to observations and GCMs (Zhang and Bretherton, 2008)

  5. LES (5) DALES SAM UCLA UCLA/LaRC UKMO SCM (16)CAM4*CAM5*CCC*CSIRO*ECHAM5*ECHAM6*ECMWF*GFDLGISS*GSFC*JMA*KNMI-RACMO*LMD*SNUUKMO*UWM* * Indicates SCMs that completed the revised runs

  6. The second round of SCM simulations Forcing revised to be the same as in LES Control case temperature and relative humidity are now directly from ECMWF Interim Analysis for July 2003 from Martin Koehler. 1. Lower troposphere above the boundary layer is warmer, with more realistic inversion height and strength. 2. More moisture in the boundary layer for LES to start with. 3. Subsidence extended to below 1000 mb, thus slightly stronger than before below 900 mb.

  7. Cloud feedbacks at S6

  8. Cloud feedbacks at S6 Round 1 versus Round 2

  9. S6 DCRF at S6 S11 DCRF at S11 S12 DCRF at S12

  10. Points to Note Some models maintain the same sign of feedbacks or negligible feedback at all three locations Negative feedback: CAM4, ECMWF, JMA, UWM Positive feedback: CAM5, CCC, CSIRO, ECHAM6, LMD, UKMO Flipped: GISS, GSFC, RACMO (in the same direction: positive at s6, negative at s12). Feedbacks at the two locations of S11 and S12 mostly show the same sign in the models

  11. S6 DCRF at S6 S11 DCRF at S11 S12 DCRF at S12

  12. Points to Note At S6, Two models show little feedback (CSIRO and UKMOL38) The small group show negative feedback (CAM4, ECMWF, JMA UWM) The majority show positive feedback (CAM5, CCC, ECHAM6, GISS, GSFC, LMD, RACMO) At S11, Two models show little feedback (ECHAM6 and LMD) About half of the models show positive feedback (CAM5, CCC, CSIRO, RACMO, UKMO) Half of the models show negative feedback (CAM4, ECMWF, GISS, GSFC, JMA, UWM) At S12, Two models show little feedback (ECHAM6 and LMD) Three models show positive feedback (CCC, CSIRO, UKMO) The majority show negative feedback (CAM4, CAM5, ECMWF, GISS, GSFC, JMA, RACOM,UWM)

  13. Instead of discussing clouds at one location at a time (the GCSS perspective), in the following, we will show all cloud types for one model at a time (the GCM perspective)

  14. CAM4 S6 DCRF at S6 S11 DCRF at S11 S12 DCRF at S12

  15. CAM4 s6 ctl CAM4 s6 p2k CAM4 s11 ctl CAM4 s11 p2k

  16. CAM4 s12 ctl CAM4 s12 p2k CAM4 ql s6 CAM4 ql s11 CAM4 ql s12

  17. CAM5 S6 DCRF at S6 S11 DCRF at S11 S12 DCRF at S12

  18. CAM5 s6 ctl s6 p2k s11 ctl s11 p2k

  19. CAM5 s12 ctl s12 p2k ql at s6 ql at s11 ql at s12

  20. ECHAM6 S6 DCRF at S6 S11 DCRF at S11 S12 DCRF at S12

  21. ECHAM6 s6 ctl s6 p2k s11 ctl s11 p2k

  22. ECHAM6 s12 ctl s12 p2k ql at s6 ql at s11 ql at s12

  23. ECMWF S6 DCRF at S6 S11 DCRF at S11 S12 DCRF at S12

  24. ECMWF s6 ctl s6 p2k s11 ctl s11 p2k

  25. ECMWF s12 ctl s12 p2k ql at s6 ql at s11 ql at s12

  26. ECMWF2 S6 DCRF at S6 S11 DCRF at S11 S12 DCRF at S12

  27. ECMWF2 s6 ctl s6 p2k s11 ctl s11 p2k

  28. ECMWF2 s12 ctl s12 p2k ql at s6 ql at s11 ql at s12

  29. LMD S6 DCRF at S6 S11 DCRF at S11 S12 DCRF at S12

  30. LMD s6 ctl s6 p2k s11 ctl s11 p2k

  31. LMD s12 ctl s12 p2k ql at s6 ql at s11 ql at s12

  32. S6 RACMO DCRF at S6 S11 DCRF at S11 S12 DCRF at S12

  33. RACMO s6 ctl s6 p2k s11 ctl s11 p2k

  34. RACMO s12 ctl s12 p2k ql at s6 ql at s11 ql at s12

  35. UKMOL38 S6 DCRF at S6 S11 DCRF at S11 S12 DCRF at S12

  36. UKMOL38 s6 ctl s6 p2k s11 ctl s11 p2k

  37. UKMOL38 s12 ctl s12 p2k ql at s6 ql at s11 ql at s12

  38. UWM S6 DCRF at S6 S11 DCRF at S11 S12 DCRF at S12

  39. UWM s6 ctl UWM s6 p2k UWM s11 ctl UWM s11 p2k

  40. UWM s12 ctl s12 p2k ql at s6 ql at s11 ql at s12

  41. 800mb 900mb 950mb 1000mb 1010mb Negative feedbacks Deepened mixed layer without much dilution at the cloud top: no explicit cloud-top entrainment and no shallow convection weak cloud-top entrainment and small moisture effect of shallow convection

  42. 800mb 900mb 950mb 1000mb 1010mb Negative feedbacks Deepened mixed layer without much dilution at the cloud top: no explicit cloud-top entrainment and no shallow convection weak cloud-top entrainment and small moisture effect of shallow convection

  43. 800mb 900mb 950mb 1000mb 1010mb Positive feedbacks More intermittent clouds due to cloud-top entrainment or shallow convection Less cloud water due to cloud-top mixing

  44. Summary • Evidences suggest that the CGILS results from some models can be used to interpret GCM cloud feedbacks. For other models, especially those displaying multiple equilibrium behavior, alternative configuration of running the SCMs may be insightful. This was demonstrated by the LMD group who added transient forcing to break up the multiple equilibriums. • Two groups of models have been identified to show the same sign or negligible cloud feedbacks at all three locations, displaying positive and negative feedbacks. It would be interesting to see if the corresponding GCMs show the same sign of cloud feedbacks. • The deciding physical process appears to be the mixing at the cloud top, carried out either by explicit cloud-top entrainment or shallow convection.

  45. Summary Comparisons with LES and with GCMs are yet to be carried out. SCMers are waiting for LES and CFMIP results.

  46. Cloud feedbacks at S11 Round 1 versus Round 2 Opposite: CSIRO ECMWF GISS KNMI

  47. Cloud feedbacks at S12 Round 1 versus Round 2 Opposite: ECMWF GISS

  48. CGILS SCM Next Steps:1. Understanding of processes in each model.2. Re-configure simulations, such as adding transience, if results are suspicious.3. Linking with GCMs4. Use LES models to say something about the SCMs

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